The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 3f4e54bd312d3dafb59daf2b97ffa08abebe60f5 Mon Sep 17 00:00:00 2001

From: Patrik Jakobsson patrik.r.jakobsson@gmail.com Date: Wed, 27 Oct 2021 16:27:30 +0200 Subject: [PATCH] drm/amdgpu: Fix even more out of bound writes from debugfs

CVE-2021-42327 was fixed by:

commit f23750b5b3d98653b31d4469592935ef6364ad67 Author: Thelford Williams tdwilliamsiv@gmail.com Date: Wed Oct 13 16:04:13 2021 -0400

drm/amdgpu: fix out of bounds write

but amdgpu_dm_debugfs.c contains more of the same issue so fix the remaining ones.

v2: * Add missing fix in dp_max_bpc_write (Harry Wentland)

Fixes: 918698d5c2b5 ("drm/amd/display: Return the number of bytes parsed than allocated") Signed-off-by: Patrik Jakobsson pjakobsson@suse.de Reviewed-by: Harry Wentland harry.wentland@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c index 17f2756a64dc..8080bba5b7a7 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c @@ -487,7 +487,7 @@ static ssize_t dp_phy_settings_write(struct file *f, const char __user *buf, if (!wr_buf) return -ENOSPC;

- if (parse_write_buffer_into_params(wr_buf, size, + if (parse_write_buffer_into_params(wr_buf, wr_buf_size, (long *)param, buf, max_param_num, &param_nums)) { @@ -639,7 +639,7 @@ static ssize_t dp_phy_test_pattern_debugfs_write(struct file *f, const char __us if (!wr_buf) return -ENOSPC;

- if (parse_write_buffer_into_params(wr_buf, size, + if (parse_write_buffer_into_params(wr_buf, wr_buf_size, (long *)param, buf, max_param_num, &param_nums)) { @@ -914,7 +914,7 @@ static ssize_t dp_dsc_passthrough_set(struct file *f, const char __user *buf, return -ENOSPC; }

- if (parse_write_buffer_into_params(wr_buf, size, + if (parse_write_buffer_into_params(wr_buf, wr_buf_size, &param, buf, max_param_num, &param_nums)) { @@ -1211,7 +1211,7 @@ static ssize_t trigger_hotplug(struct file *f, const char __user *buf, return -ENOSPC; }

- if (parse_write_buffer_into_params(wr_buf, size, + if (parse_write_buffer_into_params(wr_buf, wr_buf_size, (long *)param, buf, max_param_num, &param_nums)) { @@ -1396,7 +1396,7 @@ static ssize_t dp_dsc_clock_en_write(struct file *f, const char __user *buf, return -ENOSPC; }

- if (parse_write_buffer_into_params(wr_buf, size, + if (parse_write_buffer_into_params(wr_buf, wr_buf_size, (long *)param, buf, max_param_num, &param_nums)) { @@ -1581,7 +1581,7 @@ static ssize_t dp_dsc_slice_width_write(struct file *f, const char __user *buf, return -ENOSPC; }

- if (parse_write_buffer_into_params(wr_buf, size, + if (parse_write_buffer_into_params(wr_buf, wr_buf_size, (long *)param, buf, max_param_num, &param_nums)) { @@ -1766,7 +1766,7 @@ static ssize_t dp_dsc_slice_height_write(struct file *f, const char __user *buf, return -ENOSPC; }

- if (parse_write_buffer_into_params(wr_buf, size, + if (parse_write_buffer_into_params(wr_buf, wr_buf_size, (long *)param, buf, max_param_num, &param_nums)) { @@ -1944,7 +1944,7 @@ static ssize_t dp_dsc_bits_per_pixel_write(struct file *f, const char __user *bu return -ENOSPC; }

- if (parse_write_buffer_into_params(wr_buf, size, + if (parse_write_buffer_into_params(wr_buf, wr_buf_size, (long *)param, buf, max_param_num, &param_nums)) { @@ -2382,7 +2382,7 @@ static ssize_t dp_max_bpc_write(struct file *f, const char __user *buf, return -ENOSPC; }

- if (parse_write_buffer_into_params(wr_buf, size, + if (parse_write_buffer_into_params(wr_buf, wr_buf_size, (long *)param, buf, max_param_num, &param_nums)) {